The beta2-microglobulin/cystatin C ratio--a potential marker of post-transplant lymphoproliferative disease.

Background: As a consequence of more intensified immunosuppression, post-transplant lymphoproliferative disease (PTLD) is increasingly observed in patients after solid-organ transplantation. Beta2-microglobulin, a low-molecular weight protein (MW 11.8 kDa), is produced by all nucleated cells as part of the HLA complex.